New and Old
by The Nightly Ninja
Summary: An old Hamada returns to find that a lot of things have changed: including his family. Not only is his little brother EIGHTEEN. but he's also... a dad? oh come ON KNUCKLEHEAD. NO SHIPPING! twoshot now, may be continued if I continue to be trash for teendad!Hiro.
1. Chapter 1

"Tadashi?"

The young man in question stirs gently, before allowing his eyes to flutter open. Between the backs of his eyelids, Tadashi catches a glimpse of his almost-stress-eating aunt. When he manages to keep his eyes open he can see just why his mother figure isn't stress-eating yet: they're in a hospital room. She's bent over his bed on the right side, while two professors from SFIT stand with clipboards at the end, and a doctor stands on his left. Instantly concerned, Tadashi sits up and asks in a strangely rough voice, "What's going on?"

Cass looks like she's going to faint, the professors start writing again, and the doctor gently pushes him back down before glaring at everyone, before gently addressing Tadashi himself, "Mr. Hamada, what's the **very last** thing you remember?"

Tadashi takes a moment to think before wincing, "The fire. At the showcase building. I, uh, I tripped into something, and… who pulled me out? I-I should be dead. Even if that thing was fire retardant, I still would've run out of oxygen long before the fire was extinguished…"

"Well, Mr. Hamada the project that you tripped into was a prototype for a cryogenic freezing chamber by Krei tech. It sealed and activated itself after you fell in—4 years ago. They were clearing the last of the debris from the foundation for a new exhibition hall when they found you."

"IN OTHER WORDS" the younger professor suddenly chimed in, "you should be grateful that you're alive and value every day from this one on." She smiled warmly but Tadashi didn't hear her positivity or see her bright smile; he was too deep in thought, too caught up in the fact that he had lost 4 years of his life trying and **failing** to save his professor. _Hiro's 18 now…_ the thought was like a punch to the gut, but the next punch was more like getting hit by a truck. _They weren't looking for me, it's been 4 years, I went into a burning building and never came out, that look on Cass's face;_

"You thought I was dead." He stated before his aunt started sobbing apologies. Bus. It definitely was not a truck. "I'm guessing you guys… mourned?"

She made a choking noise "Of course we did, knucklehead! Hiro especially, h-he was… he was a disaster." Her voice was wracked with emotion, but Tadashi caught onto one word.

"Where is he… Aunt Cass please tell me he didn't—"

"No! no, he—he might have tried but… no. He's okay. He was in here just before you came-to."

Practically screaming in relief, Tadashi was then forced to do a series of simple tasks to see if the chamber-thing had any negative side effects. Seeming content, the doctor led Cass away to sign some papers so that he could be discharged while the professors left him some contact info and the instructions to call if ANYTHING seemed out of the ordinary.

Finally Tadashi was able to follow his aunt out of the room to the front door—and down another hallway, back into the maze of corridors. "uh, what are we doing?"

"I'm not sure, Hiro just texted me asking me to go to a certain waiting room. Won't answer any of my questions…" Tadashi raised a brow but followed to the waiting room that his brother had sent them to.

 _Where's Hiro?_ It quickly became apparent that the problem wasn't that Tadashi didn't recognize him (which was a huge relief); it was that he wasn't there. Cass wandered over to the reception desk and asked the man about him, but when his response came it clearly wasn't the one she wanted because she immediately screamed, grabbed his wrist and dragged him through a few more hallways until suddenly they saw a young man standing at the other end of one. He had a red tee shirt, rumpled jeans, purple bundle in his arms, disheveled black hair and a dumbstruck look on his face. Tadashi recognized Hiro quickly, aided by the fact that he was the only one in the only hallway they had stopped in. Cass took quick measured steps towards him, yet somehow, Hiro remained mesmerized by what Tadashi suddenly realized was a BABY.

"Hiro."

"Hm."

"Who's baby is that."

"Mine." Hiro's demeanor was suddenly prideful; his posture corrected itself, he got a huge grin on his face and his eyes shone with fatherly affection and pride.

Tadashi couldn't tell if he was overjoyed or if he was nauseous. Maybe some kind of mix.

"What do you mean it's YOURS."

Tadashi winced at the coldness of his aunt's tone, Hiro clearly noticed too because he looked up for the first time and gave her a determined glare, "I mean; she's my daughter."

"You're 18. You're getting rid of it."

"I don't care. Her. No I'm NOT."

"I can't believe this, you're NOT. KEEPING. IT."

"HER. I AM. KEEPING. HER." the infant started to fuss as her father started getting more and more defensive, whining in complaint as he jerked her away from her uncle, who had been reaching to take her. Considering the circumstances, Tadashi didn't get offended, instead offering his arms once again. In response, Tadashi was given his niece. He instantly zoned out of their conversation, opting to focus on his niece instead. _She looks so much like her dad I'm wondering if she has a mom at all. With the hair and the nose… eyes are different. She has… heterochromia, that's it. The brown is definetly her dads but… I wonder if the blue one even is her moms. Oh she's got my nose!_ He started nodding his head like he was shaking hands with her, interpreting her baby babble as a 'Hello! It's a pleasure to meet you!' _The pleasure is all mine your highness!_

He was laughing at his internal conversation when she was suddenly yanked from his arms. Looking up, he allowed himself back into the conversation, regretting it as soon as her heard his aunt, the one holding his niece, shout out "I'M NOT LETTING YOU THROW AWAY YOUR LIFE."

While screaming with a newborn in your arms was normally a bad decision; it was the best possible course of action in the situation because of the natural reaction: calming the shrieking child down. So as Cass Hamada started to rock the infant, the newest Hamada took her by the nose and the woman's anger melted away. When the woman drooped Hiro put a hand on the woman's shoulder. "I'd gladly do so for her." Cass and Tadashi both subconsciously nodded in agreement, even though that was exactly what they were scared of. Cass continued to hold the child as she told Hiro about all the things they would need to show to get her discharged until she traded the child for Hiro's wallet, which was given without hesitation. Tadashi wasn't sure why she paused at the door to look back at Hiro, but he was glad to accept his niece as her dad left to do paperwork.

An hour or so later, Hiro returned with a stupid grin which softened when he found his semi-conscious brother cradling his unconscious daughter. _Best day ever._ He removed her from his slumping brother, accidentally waking him up, though she continued to sleep undisturbed.

"Hey, what's" he paused to yawn, "what's up?"

"Meh, fatherhood." Hiro chuckled simply

"OH!" Tadashi yelped, suddenly seeming to remember the 2 hours prior. "jeez can't believe I'm already tired again… I just woke up."

"Well, its about 2 am, old man."

"Did you just call me _old_?"

"Well, you're older."

"Hiro I'm **23**. 19 physically!"

"uh-huh."

"whatever." Tadashi said, chuckling at his new nickname, "so what were you doing?"

"eh, birth certificate, receiving custody, signing papers, etc., etc."

"Oh? So what's my soon-to-be-spoiled nieces name." Cass came in then, sitting down with Tadashi and matching his excitement.

"You wanna know?" Hiro laughed, smiling at his daughter as she started to wake up, "how about you? Do you want to know?"

She cooed as her other relatives nodded furiously, but Cass suddenly paled, "please tell me you took this girls name seriously and gave her something she could live with."

Hiro laughed a bit, smiled devilishly, and said "Koemi Sadashi Hamada."

"Oh that's nice." Cass mused taking her from Hiro.

"YOU DIDN'T." Tadashi hissed as his brother grinned at him.

"Oh but I did you **burnt piece of toast**."

Before the eldest Hamada could respond, their aunt butted in, "Tadashi, it's a real name! you know, that's actually how your parents found your name; they found Sadashi while they were looking for girls names and decided on your name for if you ended up a boy. But they were pretty sure they'd use Sadashi." Hiro had started laughing uncontrollably while Tadashi stared wide-eyed at his aunt. "It means 'ambitious one'."

Then they turned her over to the nurse for a couple of tests before she was returned to the room, her purple wrappings making her stand out against the standard blues and pinks.

"So… where's her mom?" Tadashi asked five hours later, trying to be casual as Hiro awoke stiffly in his own plastic chair, though it was an awkward question to begin with: Hiro had apparently been forced to sit in the waiting room the whole time and Tadashi was sure that Koemi hadn't been sent to see her yet.

Hiro, jolting awake at the question, made a face before walking himself to the glass window and looking in, "She didn't want to be involved."

"WHAT!" Tadashi yelped, shooting to his feet beside his brother to stare at his niece. "How could she not…?" he let the question linger as their aunt came in with some food from the cafeteria.

Eventually, they were sitting and eating, Hiro asked "so… aunt Cass, you remember Tiffany?"

"Tiffany? That was a while ago… I… oh yeah! Yeah she was the one I told you to avoid because she was too obsessive and clingy! Tadashi, you should have seen this girl, she…" something suddenly dawned on Cass as she turned to Hiro and stared. "… her…?" Hiro nodded and Tadashi saw what she was getting at; whoever 'Tiffany' was, she was Koemi's mother.

Tadashi re-asked his previous question, causing Hiro to sigh, "she… she was a little too obsessive, like aunt Cass said, and… at the time she really wanted Emi but… she lost interest in me fast, and decided that that would extend to Emi too. She was cold and detached about the whole situation, blaming ME, even though she purposefully gave me a broken condom that night. That's why I didn't say anything; because I thought you'd just get upset because you warned me and… I didn't think I would keep her anyway. Until the ultrasound, I thought it was a solid decision. Then I was wondering if it was or not; if I should keep her or not… I kept trying to ask, but it always came out wrong and… then I was stuck in that room, then you came in to see Tadashi, and you saw me (sorry, used you as an excuse to be here)… then when Tadashi was waking up, she called to tell me that she was getting discharged, that she signed the custody over to me, that I had better, quote, get my ass over there and sort shit out, unquote, so I came over and… and then I saw her, and then I held her… I couldn't let her go like that."

16 hours later, after doing nothing but sitting in the same hospital waiting room, the family of FOUR walked out into the freezing apparently January night, when Hiro suddenly seemed to realize something. When Cass asked what, Hiro pointed out that there were only 3 seats in her truck.

"You're not supposed to have a baby in the front of the cab anyway but… I'll sit in the bed until we can figure something out." Hiro said as they got to the car where Cass had already set up the holder for the carrier.

Of course Tadashi, being himself, could physically not refrain from arguing despite knowing why he should not be in the bed of the truck in 30 degree weather, "what are you talking about knucklehead?! I'm not letting this kids dad get himself sick on her birthday! You won't be able to touch her for a week!"

"Tadashi what is it with you and extremes? You're either trying to burn yourself, or you're trying to freeze yourself! I've got more layers than you, and I wasn't just discharged from the hospital, AND you spent the last 4 years as a Popsicle, do you WANT to go back?"

Before Tadashi could deliver his bullshit argument, their aunt butted in; "Tadashi! Making Hiro be outside any longer than he has to be _isn't_ _helping_. Lets just hurry home—"

"Not too fast! She's not supposed to be in the front seat at all!" Hiro interrupted, sounding terrified.

"so that he can warm up after this. He'll be fine." She continued, ignoring the father himself.

Tadashi then clambered into the middle seat and watched his little brother shivering in the bed of the truck all the way home, and into the house; his brother made an instant beeline for the house, double checking that Tadashi had Koemi before proceeding to the fire place in the corner of the living room.

As soon as he was adequately warmed up, Hiro went up to their bedroom and started to rearrange his side of the room. As in 'I don't need this' chucking it down the stairs to the garage, or 'I guess I HAVE to keep this' pinching the few remaining items into the corner by the door leaving a large open space in the back corner between his area and Tadashi's.

The uncle himself was still sitting in the living room with his niece, TRYING to comprehend everything that happened, so coming up the stairs was a surprise for him. "Well look at that!" he laughed to the infant, "your daddy's scaring me."

"Oh really?" Hiro said wriggling his eyebrows as he walked in, taking Koemi as he did so. "Hey, Aunt Cass is gonna watch Emi while we buy some more stuff."

"it's 3 in the morning, where could we possibly be going."

"'important infants' 24 hour baby supply place. Their motto is literally just 'they're worth it'."

"Oh. Guessing the opened after I was gone. What're we getting?"

"Yeah. Uh, Furniture, clothes, a book on parenting."


	2. Chapter 2

Koemi spent the night in her carrier next to her great aunt at home while her father and uncle spent it at the store.

"Hiro, _you don't need it yet_."

"What makes you say that?"

"The fact that she's not even a week old."

"How about—"

"No."

"But—"

"NO. Hiro; what's important RIGHT. NOW."

After 2 hours of the same conversation in different isles, the brothers eventually left with a crib, mattress, stroller, swing chair and changing table in the trunk; clothes, diapers, formula, bottles and the most masculine diaper bag Hiro could find were kept in the cab with the two of them, who were still arguing about who was going to spoil her more.

The child in question was already getting spoiled rotten at home when they got there, though she seemed more than happy to accept her fathers attention as well as her great aunts when he paused to shower her with more affection as they started to move her unassembled crib, forcing his brother to wait.

When the pace started to pick up again, Hiro and Tadashi carried the crib to their room and unboxed it. So, the question is; how many geniuses does it take to assemble a baby crib? 5. And an English major; after Hiro and Tadashi left Cass apparently called their friends, who, while ecstatic about seeing Tadashi, very easily caught baby fever. They spent the first half hour of their visit cooing about their 'niece' without even acknowledging their original reason for coming. Tadashi even heard Honey Lemon talk about a quilt before Hiro called them up to help. Yet despite all the help, the whole experience was still a disaster; Wasabi broke down into tears 4 times. From start to finish, Gogo gave it a wide-eyed 'you dare?' look. Honey Lemon laughed hysterically every few moments until they were done. Fred gave up and laid face-down on the floor about 3 times. Tadashi bit his arm to keep from screaming, even drawing blood by the end. And, Hiro banged his head on the wall more times than anyone would bother to count (he actually left an indent in the dry-wall). The changing table was a similar experience, but more importantly, they were DONE. And so were the nerds.

After a small 'party' Emi got laid down and the small family started going to bed.

Then Emi woke up again and kept everyone else up for another two hours. Her dad and uncle for four.

10 minutes after her dad finally gets her back to sleep, Tadashi feels a hand on his shoulder, "Tadashi. Yo, Tadashi, I gotta go."

Tadashi glances up at his (somehow fully-dressed?) little brother and mumbles something along the lines of "where? WHY?"

Hiro only rolls his eyes, "School, Tadashi. SCHOOL. As in, sleep lightly because aunt Cass is already opening the café and you have to watch Koemi when she wakes up."

Tadashi absently nodded until he realized that his little brother was going to school 2 days after his daughter was born. "Woah, woah, woah, WAIT. Why don't you just take a day or two? You've got a _daughter_ now: shouldn't you get like, maternity leave?"

Hiro stared at him blankly. "Tadashi, you're _really_ tired and now I'm _really_ scared. A; maternity. Mother. That's for the mom. B; that's employment. And C; I REALLY wanna stay with her but…"

 _But this is for all of us._

Tadashi agreed to watch her for the day knowing that Hiro's decision was the best he could've made.

 **A/N: so, sorry about that last chapter; I forgot to clear a few things up so, if you were wondering;**

 **-Tadashi was scared that Hiro had hurt/killed himself when he first woke up because of Cass's use of past tense.**

 **-Cass looked back at Hiro when she was leaving because she saw the picture from the ultrasound in his wallet.**

 **-Tadashi thought Hiro had given her** ** _his_** **name to imply that he was girly.**

 **-Hiro had already known that Tadashi would wake up and forced himself not to freak out when he saw him, instead trying to make things normal for Tadashi (not working dude).**

 **-The nerd herd was all trying to do the same.**

 **-They all knew what was happening because they were there when Baymax confirmed it as his child, they just hadn't known that they would get to meet her.**


	3. Chapter 3

Tadashi drifted into a light sleep for a few hours as he waited for the telltale wails of his new niece, which came sometime around 9 in the morning. _Jeez, when did Hiro leave?_ Tadashi asked himself as he shakily changed the wet diaper that had awoken the child. _It must've been… I guess it must've been like 6…_

Tadashi assumed that he had 3 hours with his niece before her dad got home, paused to shudder at the idea that his little brother was a parent, and started to fix her a bottle as he started thinking again, thinking about the fact that he had missed four years of his life, of Hiro's life. _He's an ADULT, how do I deal with this? He's supposed to be 14, not a new parent!_ Tadashi was in no way placing blame on an infant, but she was most definitely disorienting him, which admittedly wasn't something he needed after suddenly being hurled into the future. _Her dad and I were supposed to be going to college together! Instead I got my own experience as a human Popsicle and Hiro got to be upset about it._

Tadashi sat his niece in her swing by Hiro's bed and turned on a little music when she was done eating, having decided to do a little research: meaning he dug through her dad's personal stuff, finding newspaper clippings, broken fragments of carbon fiber armor ( _we. Will. TALK_.), notes, poems, blueprints (Tadashi couldn't tell if he was honored or horrified that his brother had dabbled in re-animation.). He was halfway to calling it quits when he found a flash-drive. His curiosity got the best of him as he slipped it into Hiro's outdated computer and he blinked in surprise at all the videos, clicking on one of the first ones and staring at the person who showed up. It was Hiro, just not one he'd seen: clocking it at about 15, Hiro didn't look _too_ different as he grinned at the camera and suddenly held up a familiar clap board:

"Hey! Hiro Hamada here, ready for the first test of my robotics project!" he chirped cheerfully and Tadashi smiled. _This is gonna be good_ he thought, watching Hiro's machine lurch forward and tackle him.

In the next video, Hiro was sporting a huge bruise and Tadashi remembered the other reason Baymax was vinyl instead of titanium. After that, it only got worse: at some point it locked it's serrated jaw around his arm, effectively ripping it apart for Baymax to stitch back together. In each and every video that wasn't the first, Hiro had one horrible bruise or another, one thick bandage either here or there, and the standard peppering of colorful superhero Band-Aids; and Tadashi only got to the 23 test before he stopped to play with his niece who had drifted off during his search.

As he swung her back and forth, his mind drifted to her future; _what kind of person is she going to be? What type of things will she like? Will she be as smart as her dad? Smarter? Will she be as troublesome as her dad?_ Tadashi smiled at the tiny thing, noting her heterochromia again, and wondering why that one blue eye looked so familiar.

Eventually, noon rolled by, bringing with it a messy, sweaty Hiro, who had apparently done all of his classes and run home as fast as he could. Tadashi laughed at the sight of the young man who collapsed just beyond the threshold of the door, spilling across the wood flooring in a disaster of rumpled, sweaty clothing and scattered, half-finished assignments. Still, when Hiro had managed to compose himself (with no help from his brother), he was beyond happy to spend time with his daughter, ignoring Tadashi altogether, though the elder couldn't blame him; Hiro had forced himself to stay at school all morning, knowing that his daughter was at home. Tadashi was glad Hiro had the rest of the afternoon to spend withSadashi, and knew that he'd eventually get his attention. Besides, who needed more attention: the infant or the adult?

* * *

Tadashi noted a problem around 2 pm; Hiro looked sad. But it wasn't just that; at 2:30 he started to collect his stuff. At 2:45 Hiro was pressing a gentle kiss to his daughter's forehead and brushing a thumb over her cheek, whispering a little 'goodbye' as his brother realized he was leaving again. _Nononono_.

"Where are you going?" he yelped as Hiro started moving down the stairs, and the younger brother gave him a desperate look.

"Tadashi _please_ , I'm cutting it close as it is, I've really gotta go; _please_ don't make me rethink this." Gaping at his otuoto's blatant desperation, Tadashi didn't argue as the young man swept out the back door and shot away on the old moped. Though he wished he had as his niece began to protest her fathers absence in the only way she knew how.


End file.
